Q: The car is unresponsive at times, needle shows wrong fuel amounts

Hi, I'm having problems starting my car. It sometimes gets completely unresponsive after I put the key into the ignition and try to start it. Everything in the car works, including the lights and the radio. After waiting several minutes, I would then succeed in starting the car. But, there is another issue with the fuel gauge. It doesn't work correctly. The needle would move around, showing the wrong fuel amount, like empty when it's actually full. What do you think is the problem here? I appreciate your help.